In processes for the production of ceramic or refractory materials, such as tiles or the like, a drying step executed with suitable systems is notoriously included. The drying step is single for the tiles called "mono-firing", that is those materials which, after the pressing, are glazed and then baken, while it is repeated twice for the materials which afterwards are subject to a first firing to form the biscuit, then are glazed and at last are subject to a second drying step to dry the glaze and then are submitted again to a firing.
The drying, according to the traditional methods, shows disadvantages of production, installation cost, energy waste and encumbrance in the production lines.
The traditional quick driers condition the production line, so as to impose a very limited number of tile sizes, therefore different production lines are necessary to produce materials of different size and thickness, for this reason the number of production lines is often in excess with respect to the whole production of the ceramic factory.
Another disadvantage of the traditional quick driers is due to the fact that they request an enormous waste of energy that, sometimes, exceeds the 50% of the energy necessary for the firing of the same materials, also with reference to the most advanced kilns showing the best efficiency. This is due not only to the heat necessary for the drying, but also to the heat lost during the cyclic heating and cooling of the supporting structure of the same driers, besides the fact that an enormous percentage of heat is lost at the flue gas discharge.
A further drawback was caused by the encumbrances of the same driers, as well as by their remarkable cost; said encumbrances could extend both in the horizontal and vertical direction and therefore requested an excess of the shed sizing both in plan and height.
This invention tends to eliminate said disadvantages.
Said invention in fact proposes a drying installation combined with a roller kiln and developing along the same kiln, preferably below the tunnel of the proper kiln, constituting a second tunnel, suitably heated, through which the material is dried for being afterwards introduced into the firing kiln.
The savings in encumbrance, installation cost, energy and flexibility in the production of different sizes and thicknesses is enormous relative to the traditional installations.